Abstract: In a microstrip circuit having dual diode driven, independently oscillati half-wave open ring resonating sections, partially coupled quarter-wave ring sections are provided to permit matching and tuning of diodes having dissimilar negative impedances. The quarter wave ring sections are combined with appropriate line sections to accommodate the negative impedance devices. The diode circuits are connected to the low impedance points of the oscillating ring sections by the quarter-wave ring sections. Appropriate terminations to ground are provided to suppress possible oscillations in a bias circuit. Second and third harmonic traps are provided for use with TRAPATT diodes. Ground lines are provided to reduce circuit unbalance in the event of drastic power changes occuring on either side of the circuit which may other wise result in odd mode operation. Slots are provided to suppress an undesired transverse resonance mode in the line sections accommodating the negative impedance devices.

Abstract: A microstrip circuit which features a pair of open ring resonators sections adapted to oscillate independently in their even mode. In a preferred form, the ring resonator sections are each driven by a TRAPATT diode, and include a load circuit which combines the individual power outputs to a common load. Tuning stubs and the like may be provided to reactively trap harmonics in order to initiate the desired TRAPATT mode, and additional ring resonators may be interposed between the driving circuit and the load to filter the fundamental frequency, if desired. Other configurations permit power to be combined from two or more sets of dual ring resonators.